A paraphrase is a restatement (in your own words) of the ideas in the original.

Paraphrasing means reducing the length of a text but retaining the main

 Summarising involves reducing the length of a text but retaining the main

Taking a paragraph form a text and providing a source is considered as a kind of plagiarism. 

Since thoughts and  ideas are seen  as private intellectual  property belonging to the person , plagiarism is considered as a kind of theft and an academic crime. 

The most common strategy for paraphrasing involves replacing words in the source with synonyms and perhaps changing the grammar.

A paraphrase is a restatement (in your own words) of the ideas in the original.

Comparing to the original, an effective paraphrase usually should have a different structure and  different vocabulary though retain the same meaning and keep some phrases from the original which are in common use.

Quotations should not be overused because information from other academic sources should support, but not replace, your own ideas.

To show the academic contex of your research follow the basic principle: the more quotations,  the better.